Cannot redeem Galaxy Store promotion

[RickGrindskin]

I've been trying to redeem the 50% promotion offered through the Galaxy Store. I'm being presented with an error code and message shown in the attached photo (GCF4015) and have been struggling to find a solution. I have already tried clearing the cache and data for the Galaxy Store, with no results. Any advice is appreciated. 

My device (Samsung Galaxy S9 FE tablet) is relatively new and has not been tampered with, only official apps downloaded.

[0riginulll]

Have you updated your UI software? Does the Galaxy Store need to be updated? Also, try logging out and then in again.

[RickGrindskin]

My software is up to date. I tried logging out and back in. Another coupon/promotion has been added, and I cannot redeem that as well with the same error code.

[0riginulll]

Did you check the terms and conditions to see if there are any exclusions that would prevent you from redeeming a promotion? Is it region locked? Sounds like a great promotion for 50 %off wow may be too good to be true.

[RickGrindskin]

I didn't see anything that would exclude me from the offer. It's on the official Galaxy Store under the promotion/events section. I've seen others mention it for use in Honkai: Star Rail, for example. If it's region-locked, I doubt USA would be excluded..

[0riginulll]

What's the promotion called? I'll try it if I can.

[0riginulll]

I'm not sure what type of device you're using, would you mind adding that in case someone else can help --but have you tried redeeming it through the Samsung website?

[RickGrindskin]

I'm on a Samsung Galaxy S9 FE tablet. I cant seem to find any promotions/offers on the website, only the actual store app. The promotion is an "end of month" offer for specific in-app purchases. I have a listed app downloaded from the Galaxy Store. It's the second event in screenshot:

[0riginulll]

Okay I was able to get the coupon but have not decided on a game. Looney tunes looks cool, but can you win any money from the games? Have you got your coupon to work yet?

[RickGrindskin]

I have not had any luck. I've contacted support as well but it has been slow. I planned on using it for Honkai: Star Rail to save some money. Glad it at least works for someone!